Consider the following code:
Fs = 48000;
h = dsp.ParametricEQFilter('CenterFrequency', 1000, ...
'Bandwidth', 1400, ...
'PeakGaindB', 10, ...
'SampleRate', Fs);
fvtool(h,'Fs',Fs,'FrequencyScale','Log');
Let the two bandwidth $-3\rm dB$ points $f_1$ and $f_2$. Therefore: $f_1 = 300\ \mathrm{Hz}, \ f_2 = 1700\ \textrm{Hz}$
However, in the graph I see the $-3\ \mathrm{dB}$ point (i.e. the $+7\ \rm dB$ gain) at $487\ \rm Hz$. What am I doing wrong?
[cVal, normFreq] = h.freqz; freqaxis = normFreq/ pi * (Fs/2); dBval = 20*log10(abs(cVal)); semilogx(freqaxis, dBval);
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